Fluorescent lamp fed by direct current



Oct. 11, 1949. J. PESTARINI 2,484,246

FLUORESCENT LAMPS FED BY DIRECTCURRENT Filed Nov. 20, 1946 Fl (:4 Z INVENTOR.

Patented Oct. 11, 1949 UN-Ireni1smres e FLUORESCENT. LAMB FED-BY manor 1.

- CURRENT.

J oseplr'MaximusPestarini; StatenIslanmNi Y. Application November 20, 1,946,;Serial-"No. r110,975

The invention relates tolightingsystems utilizingiiuorescent: lamps. ;It is .welllknown that-for building. up the electronic column of the fluorescent --lamp, .it is. necessary to .supply, ,at .the start, a supplemental Voltage above the normal opera.- five-voltage. V

The fiuofescentlampmay be suppliedwithal- .ternating. current .or. with direct. current... The use of directcurrent is less tiring. to the eyes.

An object of the invention is to provide an improved. direct. current machine for generating the supplemental.vo1tageduring the'startin'g 'periodof the lamp.v j

A further objectiofthe invention is to..provide an improved directcurrent machine for generating a. to.tal'.vo1tage includin the supplemental starting: voltage andfthe normal. operating .voltage for aiiuorescent lamp system; Further object. of the invention is toiprovide ,means'for automatic heating Of the electrode of the fluorescent lamp using the current generated by an improved direct current machine wherein the "heating time is .limited to' that necessary for the ignition'oithe fluorescent lamp.

Still -another object of thisiinv'e'ntion is to provide animproved direct current machine in combination' with switchinglmeans for Controlling the oper'ationof the 'machine during the starting. period of the fluorescent. lamp; i 'The invention" Will be understood Withthe aid QfYthe followin description of several embodiments of the invention 'as shown in the attached drawings;

Figure lishowsa scheme fora Sy tem embodyin'gfthe invention and' including a direct current machine. Figure'z'shows an arrangement ofthe detailiof: switchgear in the scheme ofQFigu're .1. Figure 3 shows a" modified form of the-switch.- gear. Figure 4 shows another scheme of the system embodying the invention. Figure 5. shows another arrangement of. the vdirect current machine shown in Figure 1. Thimproveddirect current machine utilized in thefluorescent lighting. system described here comprises a metadyne as described in many United States patents by the applicant, see Patems Nos-2,055,240,. 1-,931413', 2,038,380, 2,049,389, and. 2,079,465. 'A more completedescription has been" given-in Revue- Generalede l Electricite, March 8th and. 15th, August 16th-.and:'2'3rd, November 22nd and 29thandlDecember- 6th;-19 30 Paris.

'I 'he metadyne, used in. this invention, may be a transformer metadyne O agenerator metadyne. Thegtransformermetadyne receives power from an electric source through primary brushes and transforms; into. electric power of anotl'ier...kin'1;l

which is suppliedito a consumer, by 'secon'clart brushes. The generator metadyne transforms mechanical power into electricpower which is supplied-to aconsumer.

Metadyne is the name .now .appliedito. the electric-.machine. developed .by the applicant. as. desc-ribediin. the foregoing Ltgatehtsnand originally referred to as transverse reaction machine.

' Figure, 1 shows the sjcherneofla general fluorescent lighting systemlemb'odying .the invention. Terminals If," 2, of adiiect current. constant .voltage network may ,lofe,v c'onnectedto terminals 5; and 'Q'with' a given current polarityv through reversing switch points 3*anjd14. 1

The fluorescent lamps "I, 8;"9,'are connectedto the constantvoltage network for normal opera;- tion thereof. Means are provided for supplying a supplementalvoltage to .the lamp 1, 8 "and 9, during the startingperiod thereof. To this end-there is provided;'aQmetadyne l0 including primary brushes. a, c, substantially short circ-uited through a switch f2, whichis closed-during the operation of the r'netadyneandfsecondarybrushes b, d'which may-be e'onnected.totlamps lg 8, 9;" The metadyne l0 is-provided-with'astator Winding I], anda switch l3 in series therewith-acrossthe line for controllingwh-ecurrent'generated' by the meta;- dyriej" *{A two" wayswitch M in one-position thereof connects'oneelectrode' of the lamp T to the "line through contacts 2|; "22. In the "other'position, switch-I4- connects the electrode to the brush" b of themeta-dyneIll'through' contacts2l, I8. iThe resistonIT-heating the electrode-of the lampTis then "traversed -"by thecurrent supplied by the metadyn'ew The electrodes and resistors in lamps 8 and 9 are similarly connected-in circuit by means of two wayswitches l5; IBQrespectiVeIy; v

' During the "starting period-of lamp .1; switches l2 and I3 are closed and the switch-M is operated to conn-ect the electrode of the lamp to the metadyne' *brush b. Immediately the 'metadyne will induce a suddenly increasing ---voltage-sufficient to ionize tlie lamp.- Immediately as the lamp is-.ioni zed, the voltage -:s-upplie i=by the 'metadyne'drops t0: the normal operating voltage of the lampmcorresponding .to the 'current supplied by the-imetadyne'; Accord-ingto the inventionpthe current traversing the stator winding H of the m'etadyneil-lfl is set at a value causing theintensityc'zof the :"current supplied by the metaclyne to be equal. to :thecurrenttraversin the lamp while operating. normallyaunder the voltage :ofthe V Figure 1,

spond to contacts of switches I2 and L3. The

network. Then the switch is may be operated to connect the electrodes of the lamp to the network for the normal operation of the lamp.

Lamps 8 and 9 may be operated in a similar manner by appropriate operation of switches I5, l6.

An initial heating of the electrodes of the lamps is usually required. This is readily obtained by the secondary current of the metadyne l traversing the resistor l1.

It is desirable that the polarity of the applied voltage be reversed from time to time. readily accomplished through the reversing switches indicated in contacts 2, 3, 4, and 6.

When the metadyne I0 is not in use and its secondary circuit is opened, the losses of the machine may be reduced by opening the switch l3 of its secondary variator winding I and thus disconnecting it from the main line or by opening the switch I2 which interrupts the primary circuit of the metadyne.

Figure 2 shows schematically a combined starting and operating switch for the correct operation of the system.

The switch comprises a handle 30 rotatable in a clockwise direction about an axis and including spaced contact members 23, 24, which slidably engage fixed contact members l8, I9, 20, 2| and '22 upon movement of the handle about axis 25. The contact members l8, 2| and 22 correspond to similar contacts indicated in The contact members 9 and 20 correswitch further comprises a dash pct 26 provided with an outlet 21 for controlling the speed of movement of the handle from a position B to position L. The handle 30 is prevented from rotating in a counter-clockwise direction by means of a ratchet 29. A spring 28 is connected to handle 30 in a manner to automatically urge the .handle towards position L when the handle has been manually moved to position B.

v When the handle 30 is in position 0, the lamp is out of service. To initiate the lighting of the lamp, the handle 30 is moved about axis 25, to the position B wherein the contact members 2| and [8 are short circuited by the contact member 23. Simultaneously the contact members l9 and 20 are short circuited by the contact member 24.

Thus the lamp is'inserted in the secondary circuit of the metadyne" as previously described. The ionization of the lamp is quickly obtained and then the handle 30 may be moved from position B to position L for normal operation wherein the contactmembers 2 l, 22, are short circuited by contact member 23. It is noted that the contact member 23 is adapted to bridge the members |8 and 22 during movement of the handle 30 towards position L whereby the lamp is shifted from the secondary circuit of the metadyne l0 tothe network without interruption of the impressed voltage. V i

It is also to be noted that the contact members l9 and 20 are of such dimensions compared to the contact member |8as to allow for a reduction of the secondary current of the metadyne to zero before the secondary circuit is opened. Thus the operator mustmove the handle 30 from the position 0 to the position'B, retaining the handle in this position a short time and then moving it to the postion L. a 1 V In '01 der to simplify the operation of the switch, the handle 30 is moved automatically from the position B to the position L by means of spring28 opposed by the dash pct 26.

This is For switching ofi the lamp, it is preferable that the handle 30 be moved in a clockwise direction from position L to position 0, thus avoiding placing the metadyne in operation. The counterclockwise movement of handle 3|] is prevented by the ratchet 29.

Figure 3 shows another arrangement for the switch, whereby the same elements, indicated in Figure 2 by the same numerals, are utilized.

The operator in starting the operation brings handle 30 from the off position, indicated by O,

we the building up position, indicated by B, and

from this position, the shock absorber 26 brings it a to the position L corresponding to the normal operation, the movement being slow enough to allow for the ignition.

The forms of the switches are given above only in order to show clearly the correct sequence of switch operation. The switch may be constructed in any other manner which provides the correct sequence of the contacts.

In the two forms of the switch, herein above described, the opening of either of the secondary Variator winding circuit II or of the primary circuit of the metadyne is accomplished. One may simply open the secondary circuit of themetadyne and leave all other circuits intact. While this will result in some increase in losses in the metadyne, it simplifies the switches.

Figure 4 shows an arrangement whereby the metadyne generator I!) supplies its secondary voltage in addition to the normal voltage of the network, permitting thus the use of a smaller metadyne. The metadyne H! in Figure 4 is shown provided with a stator winding 3| having its magnetic axis along the commutating axis of the secondary brushes b andd and being traversed by the primary current, inducing between the secondary brushes an electromotive force opposing the primary current. This allows for a reduction of the primary current when the secondary circuit isopened. This arrangement is particularly useful when the switch adopted, simply opens the secondary circuit of the meta dyne and leaves all other circuits intact;

Figure 5 shows a simil'ar'scheme of the plant with a metadyne 32 operating as a transformer metadyne. The latter is shown provided with two separate armature windings. Each armature winding is connected to a separate commutator. One commutator bears the two pri mary brushes a and c and the other commutator bears the two secondary brushes 7b and d.

The transformer metadyne. 32 is shown provided with two stator windings 33 and 34. The winding 33, operating alone, is set'to cause the secondary current to be zero and the winding 34 inserted by closing theswitch I3 is set to cause by its ampere turns the creation of a secondary current having the necessary intensity required by the lamp in normal operation. Thus when the switch I3 is opened, the secondary current drops to zero.

On Figure 5 the transformer metadyne 32 is shown with its primary circuit connected to the network through the ,switchl2. The primary brushes may be connected to an independent source of current and in this case the armature may be provided with only one winding.

It will thus be seen that means are provided for inducing the peak of voltage necessary forth e ignition of fluorescent lamps, for automatically reducing to zero said peak of voltage immediately after the ignition is achieved, for providing an automatic heating of theelectrode just before gas-e246 the ignition andforahtdmaticallyweasingr:said heating as"soon a's th'e' ignition is accomplished;

it: -is" further apparent that? several "variant .arrangementsr'aredisclosed:iontne-metadynethat creates said peak I of xvoltag; vfand lthat.varioiis ..arrangeiiientsziorzthe correctswitcligearrare :pro-

.vided; in which :the several .obiects' rot". the. invention:areiachieve'd.

tion ofna direct current network of a fluorescent .lampcomprising electrodes and an ionized-col:-

.ummbetween said electrodes, and a transversere- .action ;rnachine provided with primaryvand secondary pairs of brushes means for connecting theelectrgdes of said fluorescent lamp to thelsec- ,ondarybrushes of saidtransverse reaction imachine whereby a peak yoltage is applied between said: electrodes during the ignition period of the ion zed solemn mean o co t ling the tene sity of the current supplied by said transverse ad ed-mach n ;b eath la Qo p e a tor winding having its magnetic axis substantially coincidingt'withijthe commutating axis of said secondary brushesa ndset to cause said suppliedcurrent' to'be-substa'ntiaily equalto the current necessary for normal operation of saidlamp whereby thepealnof volta efiinduce'dib'etween said electrodes drops to the normal operating voltage ,of. meg-im at the termin .l2iQ 0f said. ignition period an'd mearrsfor connectin gfthe lampto'sja'id network at the termination "of said "ignition period.

2. In an electric lighting system, the combination of a direct current network, of a fluorescent lamp comprising electrodes and an ionized column between said electrodes, and a transverse reaction machine provided with primary and secondary pairs of brushes, means for connecting the electrodes of said fluorescent lamp to the secondary brushes of said transverse reaction machine whereby a peak voltage is applied between said electrodes during the ignition period of the ionized column, means for controlling the intensity of the current supplied by said transverse reaction machine to the lamp comprising a stator winding having its magnetic axis substantially coinciding with the commutating axis of said secondary brushes and set to cause said supplied current to be substantially equal to the current necessary for normal operation of said lamp whereby the peak of voltage induced between said electrodes drops to the normal operating voltage of the lamp at the termination of said ignition period and means for connecting the lamp to said network at the termination of said ignition period, a resistor for heating said electrodes and means for connecting said resistor in the circuit supplied with current by said transverse reaction machine, means for successively switching said electrodes from the circuit supplied with current by said transverse reaction machine to said direct current network, and means for simultaneously disconnecting said stator windings of said transverse reaction machine from said direct current network.

3. In an electric lighting system, the combination of a direct current network, a fluorescent lamp comprising electrodes and an ionized colj l t Qsiati 6 urnntiietweeni"said electrodes"".and: iztransvers reaction'widirect current. 'generatoriprovidedwwith primary and z'secondary ipairsifo't'v brushes and :includirigrstator windings; .ineahsifor substantially short circuitingrtsaidf primary' brushes ".of: said transverse reaction generator, meanst'forx connecting tsaid vlampnto athe; secondary :brushes: of

.said. transverse reaction "genera-tori whereby 3a peak" :voltag'e- :is zapplied-rbetween- .sa-idelectrodes .during: the ignition; period" ofthe ionized? column; rmeans .for controlling the intensity of Y the current;- supplied -.byisaid transverse:reaction ma- -Chl11'8s1t0 thelampcomprisingaone ofr said stator windings-having; its magnetic axis substantially ,coinciding with thei-fcommutating :axis of; said .secondary brushes--and setgto cause said supplied ,current {to be substantially equal to; the cur,- erent nece sary ifor -.norma ;.op rat on. of sai amp', he .by-* th m a rv aee vi d ccdbetween sai e trode o stohe tone zi r ties11vo tas et am -at th t rm nation of sci. i ion. Per qQ-aed. means e on ec i s the em 't-os ienetW k 'ihe m nation of said ignition period.

- ..I an.e i s as lr le ii eeemhieer i fe f di eei surreatzeet o fluo escen am .saim d sleitrede and an; l e s0 vm betw en: a dze seeiqsl een a ement r g e orator provided with T p bru hes and i short' circuiting'said primar r us'hes' o f; sai d tran rselr aeiieeseee at i ee fi eaq s "isszihdiiins aee ciremh re iefq be ween was ene siasi jeswee -t a arylbrushe means fr connector i h swa it: assesses irae e s .isa essene aw nlie i v a-e'ea voltage is" applied b'tween said electrodes during the ignition period of the ionized column, means for controlling the intensity of the current supplied by said transverse reaction machine to the lamp comprising another of said stator windings having its magnetic axis substantially coinciding with the commutating axis of said secondary brushes and set to cause said supplied current to be substantially equal to the current necessary for normal operation of said lamp, whereby the peak voltage induced between said electrodes drops to the normal operating voltage of the lamp at the termination of said ignition period and means for connecting the lamp to said network at the termination of said ignition period.

5. In an electric lighting system the combination of a direct current line, a fluorescent lamp comprising electrodes and an ionized column between said electrodes and a transverse reaction direct current generator provided with primary and secondary pairs of brushes and including stator windings, means for substantially short circuiting said primary brushes, means for connecting one of said secondary brushes to said line, means for connecting the other of said secondary brushes to one of said electrodes, means for connecting the other said electrodes to said line, whereby a peak voltage is applied between said electrodes during the ignition period of the ionized column, means for controlling the intensity of the current supplied by said transverse reaction machine to the lamp comprising one of said stator windings having its magnetic axis substantially coinciding with the commutating axis of said secondary brushes and set to cause said supplied current to be substantially equal to the current necessary for normal operation of said said ignition period. A

lamp whereby; the peak voltage-1 induced between said electrodes drops to the 'normal operating voltage'of: thelamp. at the terminationof said'ignition period and means for connecting the lamp to said network at the termination of said ignitionperiod.v 6. In an elec tion of a direct current line, a fluorescent lamp comprising electrodes andian ionized column between said electrodes, and a transverse reaction direct current transformer provided withlprimary and secondary pairsof brushes, and includin stator-windings, means for connecting said primary brushes to said direct current network'substantially at constant voltage, and meansfor connectingsaid secondary brushes to said electrodes whereby a peak voltage is applied between said electrodes during theignition period of-the ionized column, means for controlling the intensity of "the current supplied by said transverse reaction machine to the lamp comprising one of'said stator windings havingits magnetic axis substantially coinciding with the commutating axis of said secondary brushes and set to cause said supplied current to be substantially equal to the current necessary for normaloperation of'said lamp, whereby the peak voltage induced between 'said electrodes drops to the normal operating voltage of the lamp at the termination of said ignition period and means for connecting the lamp to said network at the termination of '7. =In an electric lighting'system, the combination of a direct current line, afluorescent lamp comprising electrodes and an ionizedcolumn between said electrodes and a transverse reaction direct current transformer comprising stator windings, primary and secondary pairs of brushes,

trio lighting system, thecombina- 7 Fa. pair of armature-windings "and a pair of commutators, one of said commutators coacting with said primary brushes, the other of said commutators coactingzwith said secondary brushes, means for connecting said primary brushes to said direct currentline andmeans for connecting one'of said secondaryv brushes to said line and means for connecting the other of said secondary brushes to one-of said electrodes and'means for connecting theother electrode toithe said line, whereby'a peak voltage is applied between saidlelectrodes durlng' the ignition period of the ionized column, means for controlling the intensity of the current supplied to the lamp by said transverse reaction transformer comprising a pair of said stator windings having their magnetic axis substantially coincident with the commutating axis of s aid secondary brushes, one of said stator windings being set to cause said supplied current to' be substantially equal to zero and theother of said stator windings being set to cause said supplied current to be substantially equal to the current necessary for normal operation of said lamp whereby the peak voltage induced between said electrodes drops to the norma1 operating voltage of the lamp at the termination "of said ignition period and means for connecting the lamp to said network at the termination of said ignition period.

JOSEPH MAXIMUS PESTARINI;

REFERENCES CITED UNITED STATES PATENTS of record in the Number V Name Date 1,895,361 Zecher et al. Jan. 24, 1933 2,038,380 Pestarini Apr. 2 1 1 936 

